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TELEPHONE TRANSMITTER No. 310,151. Patented Deo.. 30. 1884.

WITNESS JJVVEJVTOR @41 .Html-nay UNITED STATES PATENT OFFICE.

J. HARRIS ROGERS, OF WASHINGTON, DISTRICT OF COLUMBIA.

TELEPHONE-TRANSMITTER.

SPECIFICATION forming part of Letters Patent No. 310,151, dated December 30, 1884.

(No model.)

To all whom it may concern,.-

Be it known that I, J. HARRIS Roenes, a citizen of the United States, residing at Vashington city, in the District of Columbia, have invented certain new and useful Improvements in Telephone-Transmitters, of which the following is a specification, reference being had therein to the accompanying drawing.

My invention has relation to telephonetransmitters, and more particularly to that class known as gravity77 transmitters,where in springs and their equivalents are dispensed with, whereby the construction is greatly sirnplied and a uniform and regular adjustment obtained for an indefinite length of time; and to these ends the novelty consists in the construction, combination, and arrangement of parts, as will be hereinafter more fully described, and particularly pointed out in the claims.

The figure inthe drawing is a side eleva tion illustrating my invention.

Ais the mouth-piece; B, the carbon diaphragm, upon which rests the plane basea of the carbon button O. The top c of this button is convex in form, and it lits into a correspondingly-concaved recess, D, in thecarbon bar or rod E. The rear end of this rod E has a hole, e, through which passes a staple, c, by means of which the said rod is hinged to the case, (not shown,) so as to have a free vertical movement. j

F is a metallic weight sliding along the rod E and secured in place by the set-screw f. This weight is provided with a connecting- Wire, G, passing through the primary of the coil H, thence through the battery I and back to the diaphragm B.

M N are secondary wires of the coil H, and run to the main line and telephone-receiver in the usual manner. The transmitter being connected to the line, the adjustable weight F is moved along the rod E until the proper adjustment is attained to correspond with the line on which it is used, and when the best result is obtained the weight is secured in place by the set-screw f, and while the line and battery are uniform there will be an even and regular result without further adjustment, which is not the case where spring or xnercu ry `adjustments are employed, owing to the changes produced by the variations in temperature.

By making the base a of the button Ca perfeet plane to correspond with the upper face of the diaphragm B, and the top c of said button convex to correspond to the concave recess D in the rod E, the button is securely held in place in such a manner as to allow the greatest freedom of motion of the parts, so that it will respond with extreme sensitiveness to the voice.

Having thus fully described my invention, what I claim as new and useful, and desire to secure by Letters Patent of the United States,

l. In a horizontal-diaphragm transmitter, the combination, with a hinged-rod electrode, ot' a button-electrode, held in place upon said diaphragm, which is in circuit with said electrode, by the gravity of said bar, as set forth.

2. The combination, with the horizontal diaphragm B, having loosely resting thereon the plane base a ofthe button C, of the hinged rod or bar E, having a recess, D, corresponding to the convex face c of the said button, provided with circuit-connections, as and for the purpose set forth.

3. The combination, with the diaphragm B and button G, loosely resting thereon by gravity, of the rod E, having the adjustable weight F, and the circuit-connections, as and for the purposev set forth.

In testimony whereof I affix my signature in presence of two witnesses.

J. HARRIS ROGERS.

Witnesses; Y

H. J. ENNIs, Jas. C. RoeERs. 

